Modelling,simulation and evaluation of ground vibration caused by rail vehicles*

ABSTRACT

There is a great need to develop rail networks over long distances and within cities as more sustainable transport options. However, noise and vibration are seen as a negative environmental consequence. Compared with airborne noise, the related problem of ground vibration is much more complex. The properties of the ground vary significantly from one location to another. There is no common assessment criterion or measurement quantity and no equivalent to the noise maps. Ground-borne vibration is transmitted into buildings and perceived either as feelable whole-body vibration or as low frequency noise; it can also affect sensitive equipment but it is generally at a level that is too low to cause structural or cosmetic damage to buildings. A review is given of evaluation criteria for both feelable vibration and ground-borne noise, empirical and numerical prediction methods, the main vehicle and track parameters that can affect the vibration levels and a range of possible mitigation methods.     

区域与次区域交通模型的一致性研究——以南加州橙县和尔湾市交通分析模型为例

介绍了区域交通模型和次区域交通模型，以及两种对接方法。以美国南加州橙县和尔湾市交通分析模型为例探讨实现交通模型一致性的具体过程。首先通过构建3级交通分析小区系统，运用土地利用／社会经济数据转换系数，以及遵循同区域交通模型相一致的公路网构建方式确保模型输入数据一致；同时，对次区域交通模型的模拟结果进行适当后处理，使其与实际交通量吻合。结果表明，尔湾市交通分析模型与橙县交通分析模型之间的结果差异为．4．2％，可认为二者之间是一致的。     

可编程控制器在潜艇集中控制系统中的应用

介绍一种便于实现且功能较全面的硬件电路控制系统,它是海军舰艇设备改造的理想设计实现方案.系统采用OMRON CJ1M PLC与一台计算机构成集中控制系统的基本框架,利用以太网实现控制器与及计算机之间的信息传输,给出了潜艇集中控制系统部分控制程序的流程图.该设计方案已经在实验室环境下调试完毕.     

基于管理型财会人才培养的教学模式探索

文章以浙江工商大学的＂管理型财会人才培养模式创新实验区＂为例,对其在教学模式中的创新与实践进行分析,提出了进一步改革的思路。     

浅谈连拱隧道中导洞法施工技术

该文以实例介绍了连拱隧道中导洞法的施工技术在吉怀(吉首到怀化)高速公路第4标段龙子康连拱隧道的施工中,以过去的三导洞施工工艺为基础,在Ⅳ级以上的围岩地段,取消两边的侧导洞,直接采用中导洞法施工,简化了施工工序,减少投入,加快施工进度。     

Land Changes and Conflicts Coordination in Coastal Urbanization: A Case Study of the Shandong Peninsula in China

The coastal zone is an interaction region between land and ocean and an interface of geosphere, hydrosphere, atmosphere, and biosphere, as well as greatly affected by human activities. Driven by economic activities and increased population, urbanization is rapidly developing in coastal zones, and a series of land resource and environmental conflicts have occurred, especially in developing countries at times of economic transition. This article reports a case study of the Shandong Peninsula of East China. We analyze the land-use practices and land cover changes of six cities over a timeframe of nearly a decade. We then review the management conflict issues. The most commonly encountered conflicts fall into three categories: those between expanding constructed land and decreased cultivated land; those between land resource utilization and conservation; and those between increasing demand for land and degrading land quality. All in all, they reflect the fundamental conflicts between short-term economic development gains and long-term food security and ecosystem sustainability. This article puts forward an institutional approach to coordinate these conflicts so as to realize integrated and coordinated coastal management.     

仰拱及调平层渗漏水处理及隧道路基排水设计优化思考

以某隧道施工过程中出现的仰拱及调平层渗漏水的处理为例,分析问题出现的原因,得出在隧道设计阶段,采用中央排水沟进行隧道排水的必要性,达到提高隧道路面使用耐久的目的。     

Challenges and Myths in Norwegian Coastal Zone Management

Abstract

This paper is written in response to a recent publication (Walker, 1973) which questions both the biological basis for wetlands preservation and the usefulnesss of scientific participation in the formulation of management policies. Our major points are that: (1) considerable evidence exists linking wetlands primary production to aquatic secondary production, (2) all available information suggests that large‐scale wetlands destruction results in lowered production of estuarine organisms of interest to man, (3) more than economics needs to be considered in attempts to analyze the procedures by which the wetlands controversy is to be resolved, and (4) uncertainty about the applicability of scientific findings to a particular problem situation does not destroy the usefulness of those findings in reaching a solution to a public controversy.     

铁路集装箱中心站班列编组方案数学模型

针对已开通运营的铁路集装箱中心站相继开行诸多集装箱班列的实际,构建了集装箱班列编组方案选优的数学模型.该模型是在借鉴已有列车编组计划优化模型的基础上,根据其运输组织的特点,建立了在路网情形下,考虑了包括车站班列中转改编能力储备约束和区段牵引定数限制因素在内的单组班列编组方案选优的数学模型.该模型将一支集装箱箱流可能需要二次及其以上中转改编问题转变为多次一站中转改编问题来描述.因而,该模型复杂度大为降低,且为线性0-1规划模型,决策变量规模为2n3 - 5n2+3n.因而,该模型可以应用现有较为成熟的线性规划算法进行求解.另外,该文还运用模型实例来说明该模型对实际问题的有效描述.     

The Quiet Revolution in Visual Resource Management: A view from the coast

Abstract

This introductory piece traces the growth of knowledge and activity associated with visual resource management in general. A specific framework of questions regarding methods of coastal zone visual resource management is presented. The state‐of‐the‐art in methodological studies is listed for each question, and the methodological questions are related to the major articles with the special issue of the Coastal Zone Management Journal. Major legal federal statutes, state statutes, and court cases are reviewed in light of visual resource management in the coastal zone. The remaining articles within the special issue that deal with integration of VRM into decision‐making are then arrayed against a management framework. This framework includes regulatory situations for (1) public land management and planning, (2) public projects involving private lands, and (3) public regulation of private projects.